I am not a diesel mechanic but I try to capture what I learn as I work through different issues. I read everything I can find about the early L-Series Tractors. I understand the L175, L210, L225, L225DT, and L260 are essentially the same tractor except for differing engine size. Also the L225/L225DT has a 3 cyl engine and the 225DT has 4 wheel drive components. If you know other wise, let me know. I think the 1969-70 L200 is somewhat like these but didn't have headlights.

Sunday, October 07, 2007

A Sad Day

I sold my tractor. My beloved L210 went to a new home. We sold the house in the country and are going to move into the city for a awhile. I let all of my manuals and reference materials go with it. I'll leave the blog up for now. If there's anyone that is interested in taking over the blog, let me know.

Tuesday, July 03, 2007

Brake Shaft Bearing Repairs

When I opened the right brake housing to assess what was going to be necessary to repair the brakes, I got an outpouring of transmission gear oil. The whole housing was full. The drum and shoes were swimming in it. After getting it drained and pulling the drum, it was obvious why. The shaft seal was warped and deformed beyond any semblance of symmetry. I pulled the 4 bolts that hold the housing on and tapped it loose. It came off easily but destroyed the gasket in the process. The bad news was behind the brake housing.

The brake shaft bearing was shredded. Most of the inner bearing race was intact on the shaft but the outer race was in shards. Only one of the ball bearings was even visible. The rest had made their way to the bottom of the case. Since I've put hundreds of hours on it and I'm assuming this didn't just happen, I'm going to leave the loose ball bearings where they are. I couldn't find a simple way to get to the inside of the differential.

I took the brake shoes to a place in Tacoma. They relined them for about $75.
I got a new brake shaft bearing and seal from McGuire's Bearing in Tacoma. $14 for the bearing. $2.50 for the seal.
I got the shaft collar and O-ring from a Kubota dealer. Jennings Equipment in Puyallup, WA. $52.00 bucks for a simple machined collar. I had a local machinist knock off a duplicate for $25.00.

Jennings Equipment removed the old bearing race and pressed the new bearing onto the shaft for about 20 bucks.

Reassembly was easy except for accidentally breaking the brake rod at some point. I'll need to borrow a welder to fix it.
I had to make gaskets. Scissors and a hole punch speed the process.
The easiest way to put the springs back in the brake shoes is to hook both springs into place on the shoes and then flex them onto the cover assembly.

While assembling, pay attention to the fact that when installing the housing cover with the shoes in place, the brake came goes to the forward of the housing and also note that the arm that goes on the cam is not symmetrical and you need to install them so they are parallel. I think as the brakes wear they can be flipped to take up a different amount of play.

Sunday, June 24, 2007


I took the brakes apart today. It wasn't pretty. Right side brake housing was completely full of gear oil. The brake drum shaft bearing was shattered and the seal was dysfunctional. We're talking disaster. I've got to find a replacement bearing and seal bushing. Meanwhile I needed to get the shoes re-lined. The drums aren't too bad, This is still going to be much bigger than I wanted.

Somewhere in the bottom of that transmission case, there are about a dozen hardened steel balls rolling around the remains of the crushed bearing races. It gives me terrors just thinking about it. Anyone know the least intrusive way to clean the sump of the tranny/differential case? Anyone ever removed the PTO shaft from the rear? The panel directly in front of and below the seat looks like it may be a way in also.

The good news about working on the L210 is that any mechanical assembly I've ever disassembled has been completely straight-forward to repair and replace.

Sunday, June 10, 2007


Traffic on the site seems to have picked up lately but I don't know why. Usually it's winter "hard starting" season that brings folks around.

My L210 has been a faultless trooper this spring. Starts on the second or third revolution everytime. Nuts and bolts not rattling loose like they did when I first got it. It's time for an oil change though. It needs new brake pads and new seals on the brake drum shafts too. Time to break out the tools. If there are any tricks to that brake job, I'll tell you how that goes...

Sunday, February 11, 2007

Is Your Voltage Regulated?

Hard Starting? Make sure your battery is fully charged. It needs to be charging at about 14.5 Volts to stay pumped above 12.5V where it should be. If it drops below 12V don't expect to be starting a diesel.

I bought a battery charger and charged my battery to the top. It made a serious difference. My voltage regulator isn't regulatoring like it should. I wonder how many good batteries get replaced when it's the regulator. Anyone know a good substitute for the stock regulator.

Wednesday, January 10, 2007

More From Larry About Hard Starting L1500

I rearranged these to read oldest to newest...

On Jan 4, 2007, at 4:32 PM, Larry wrote:

Thanks for the info. I spent some time today going through the entire glow plug circuit. Cleaned off all the electrical connections on the dash mounted starter switch and even removed the glow plugs and cleaned them also. I tested the glow plugs while they were removed and they are both getting red hot so I know the circuit is working ok. Tried starting it after all this and still had the same problem. Even though the starter seems to be turning over ok I'm thinking that it's just not spinning over fast enough to fire the engine. The starter was taken apart and cleaned about a year ago but I guess I need to take it to a starter shop so they can check it under load. Do you know if these tractor starters can be rewound to give them more starting torque? Thanks again for the info you sent. It was helpful.

From: Mike
To: Larry
Sent: Thursday, January 04, 2007 7:56 PM
Subject: Re: Kubota L1500

Also, how strong is your battery. If it isn't spinning fast enough, dirty terminals and weak battery are more likely than starter. Does jumping it from a running vehicle help? I'd check compression next. Starter is a pain to remove on mine, you have to disconnect the hydraulic lines.


From: Larry
Subject: Re: Kubota L1500
Date: January 5, 2007 4:04:30 PM PST
To: Mike

Was determined to find the problem so I spent most of the day changing out both battery cables and removing the starter then having it checked out at a starter shop. Starter checked out ok but it does seem like the problem was in the cables. The positive cable seemed to be OEM and it was made of aluminum which I changed to a copper cable. The ground cable seemed ok at first until I started bending it and it began to break apart. Changed that one to copper also. The engine is spinning over fine and starting a whole lot better than before. I think the engine is still a little sluggish getting started but this might be fuel related. At least it starts a lot better than before. Mike, thanks again for all the help.

Sunday, December 31, 2006

Glow Plug Circuit Check

I got an e-mail from a reader. I post this with his permission:
From: Larry
Subject: Kubota L1500
Date: December 30, 2006 6:57:33 AM PST
To: ironcross11-at-earthlink.net

Just read your articles regarding hard starting on some model Kubota tractors. I have a Kubota L1500 (same as the L175) and have always had problems starting the engine. Starter has been rebuilt, new battery installed but starting it in cold weather is impossible. I seem to have good compression and the engine does puff white unburned smoke when cranking the engine. I'm not sure what amperage the glow plug circuit should supply to the glow plugs, so I haven't tried reading it. Do you have some knowledge of the glow plug circuit that you could pass it on to me? I do see the indicator coil on the dash begin to glow when activating the glow plugs but don't know what it goes through after this on it's way to the glow plugs. I would appreciate any info you could give me.
I replied:
From: Mike
Subject: Re: Kubota L1500
Date: December 30, 2006 6:57:33 AM PST
To: ironcross11-at-earthlink.net

If it's like mine, power should go from the Key switch to the heating switch to the indicator coil to a big coil resistor (under the battery on mine)and then to the glow plugs. It's all a series circuit so if any part isn't working, none of it should work unless you have a short. Here is the schematic from my cheesy reprint manual.

The check for a short is easy. Without disturbing anything else, very carefully disconnect the second glow plug in the circuit from the ground. If it the glow indicator still lights--you have electric shorts!

If it doesn't glow, have an assistant close the glow plug heater switch and then rattle the wiring harness around (in a dimly lit area) and look for sparks or jumps on the ammeter (if so equipped).

If you still are not sure, reconnect the last glow plug to ground and disconnect the first glow plug from the circuit. Close the heater switch and check voltage from the open lead to the glow plug. It should be pretty close to battery voltage. If it isn't, you are probably shorting to ground somewhere else.

When I heat my glowplugs it nearly pegs the ammeter, but it did that when it was shorting too. So that isn't a reliable diagnostic by itself.

Apologies for the shoddy quality of the scan: the numbered items are:

1 Glow Plug
2 Glow Plug Resistor
3 Glow Plug indicator Coil
4 Starter/Glow Plug Switch
5 Key Switch
6 Voltage Regulator
7 Alternator/Generator
8 Battery
9 Starter

The Glow plug descriptor reads: 15101-65511 Nippon Tokusho Togyo Make
Direct current 1.5V 40 Amp

Sunday, December 03, 2006

More Hard Starting

It's that time of year again. Traffic on this blog always picks up when it's cold. Guys that used their diesel tractors all summer without problems are wondering why they won't start.

Before we go any further: Stop cranking the tractor if it won't start in 2 or 3 revolutions. You're putting unnecessary wear on the engine. Typically, if a diesel won't start in three or four seconds - it won't start. There are some exceptions in the case of injector bleed down or dry rings, but mostly it's not going to get better by cranking.

I wrote extensively about it here last winter.

One of the dynamics is the physics of Lead-Acid batteries. Over time, heat reduces their potential to generate current. But then it's compounded because when they are cold they actually can use less of their available potential. So over the summer, your battery was being decayed by heat and now the cold saps it of the ability to release the remaining energy. Even with gasoline autos, most starting problems appear in the winter.

Make sure your glow plugs are actually heating. I had a short last year and my glow plug indicator was lying to me.

You can try force feeding your diesel with a 1500 watt blow dryer or a heat gun, but I'm not sure that will make any difference with an ice-cold oil bath air filter. Let me know how that works out.

Tuesday, October 31, 2006

Glow Plug Surprise - Reprise

It was cold (for here) last night. It went down to 21F. This provided the perfect opportunity to see if the glow plug wiring repairs I did in June were up to the task and also check if the engine was sound enough to start when cold. Hoo-Hah! Heated up the glow plugs and she fired to life on the third revolution after sitting for over a month. Only one cylinder fired at first and it took a little time before the other kicked in. That can't be good for it, but it's better than using ether.

Last winter I struggled with unpredictable starting. Well, let this be a lesson. The glow plugs won't heat if they're shorted out of the circuit.

Sunday, June 18, 2006

Glow Plug Surprise

If you are having starting issues when it’s cold, check the WHOLE glow plug circuit.

Recently I happened to be standing on the left side of the tractor while starting it. (Made sure that it’s out of gear) While I was heating the glow plugs, I saw a small spark. Investigation revealed several bare spots on the wire that runs from the resistor coil under the battery to the rearmost glow plug.

Over the winter I had very quirky starting. Now I think I had intermittent glow plug performance.

If you want to rule out this issue, disconnect the glow plug from power wire and then see if the resistor coil and dash indicator still heat up. If they do, you have a short that’s cutting your glow plugs out of the circuit.

By disconnecting the wire from the resistor coil that runs the glow plug, I was able to manipulate the wire enough to wrap the whole length of it in electrical tape.

I won’t know until next winter whether that was the main issue causing unpredictable starting, but if it was, it might explain why the guy sold the tractor so cheap.

Sunday, May 14, 2006

The Starter

For 55 bucks, a nice guy named Eric put a new pinion gear on the starter. In fact, it is one of those high amperage gear reduction units I alluded to in the earlier post. Apparently the contacts on the cable from the battery were oxidized because now that it's been brushed off and tightened down, that thing cranks like a demon. I did some minor mods to it to make it easier to install. I ground down the nuts and the stud that takes the power from the relay to the motor to shorten them down by about a quarter inch. I did the same to the main power stud that gets power from the battery.

I also rounded the stud that gets the power from the ignition switch. By doing this the installation was tons easier and put a lot less stress on the hydraulic lines.

Remember, if you are going to grind studs or screws, put a nut on the stud so you can back the nut it off to clean up the threads when you're done.

Wednesday, May 10, 2006

Busted Tooth

The starter was making a heinous noise so I had to pull it. One of the drive pinion teeth was broken off. I had to disconnect the hydraulic line that feeds the pump where it connects at the bottom of the hydraulic fluid tank. Naturally that requires draining the hydraulic tank. Off to the auto electric shop tomorrow to see if they have a replacement drive assembly. That and 7.4 quarts of # 140 Turbine oil. By the way, the pinion had 11 teeth. The manual says the OEM starter had 9 teeth.

Sunday, April 16, 2006

Maximizing Your Loader

I've moved scores of yards of dirt around the property with my Kubota. A two-wheel drive tractor with a loader faces some challenges as an earth mover in hilly ground, but it will get the job done. One of the most important things you can do is get as much weight on the back wheels as you can. Without some counter-balance, t won't back up hill with a full bucket. I put my heavy old tiller on the three point hitch and it makes all the difference.

I was thinking about making a block of concrete with 3 point hardware cast into it. I have no idea how much would be the ideal amount, but so far, the more I can get on the back wheels, the easier it is to back and steer with a full bucket.

Tuesday, February 28, 2006

Kubota L200, L210, L260 Oil Filter

Oil Filter -- I had a little bit of trouble finding the right listing for the oil filter. Mine takes one of these cartridge types and the part #70000-14621 and you can find it here. Doing the oil change in accordance with the service manual is a simple but time consuming job. I wrote about it here.

I’d seen that some models were made to take normal spin on filters and there may be a retrofit to adapt your tractor for spin-on filters. In fact, I saw an L210 with a spin-on today. Man - I'd like to get one of those filter heads that take the spin on filter.

Monday, February 27, 2006

L175, L210, L225, L225DT, L260 Headlight Lamps

Headlight Lamps -- 70' to 72' L210 headlights take a bulb with an uncommon base design. The folks at the local auto parts store had never seen one like it. But if you need some, try looking up 6235Y or go here to pay $11.53, Here to pay $1.99, and here to pay 46 cents.
It should also be the same bulb for the early model L175, L225, L225DT, L260 and maybe some others.
Pull the old ones before you order to make sure what you see on the order page is what you need.
Instructions for getting them out of the sockets are here. Don’t forget to send me some money if this saved you some.

Sunday, February 26, 2006

Hard Starting

Volumes have been written about starting diesels – especially when it’s cold.
Bottom line – The fuel air mix has to get sufficiently hot to spontaneously ignite. Fuel and ENOUGH Compression are all you need. But the devil is in the details.

Rule number 1: If the engine doesn’t rotate fast enough, it won’t start. Even a new engine won't start if it the starter won't crank it fast enough.

Start with a kick-ass battery. Diesel compression goes to 450 PSI. In a small cylinder that has 10 square inches of piston surface, that means 4500 lbs of pressure at Top Dead Center. I had winter starting problems that all went away when I replaced a 5 year old 575 CCA battery with a brand new 850CCA battery. Make sure the terminals and cable lugs are clean and tight on both ends of the main power cables. You want 4 gauge cables to prevent too much voltage drop.

Starter – A new OEM starter is hard or impossible to find. Here is a place that rebuilds them. The original starter had a .9KW draw. Thats 75 Amps. There's new starters out there that draw 210 Amps.

I’m not sure if it's a good thing, but my tractor has a Nippon Denso manufactured John Deere starter. It’s part number RE51447. Denso Part 028000-8401. I think the OEM starter has a 9 tooth pinion but the pages about the JD starter here and here say it is 10 or 11 tooth pinion. I have not removed it to count the teeth.
There are now some gear reduction starters that translate higher motor speeds into more torque. If I need to replace my starter, I’m going for the “high torque gear reduction unit”.

OK – Good battery, clean terminals and connections, dash lights power up when the key is turned on, glow plugs heat as designed. When you crank it, you should see at least 400 RPM on the tachometer and 400 RPMs will be enough if compression and fuel are working.

White exhaust when you crank is unburned fuel, it's getting fuel but not enough heat to fire. It's usually insufficient compression or not cranking fast enough. It means the compression is good enough to vaporize the fuel, but not enough to combust it. If you are seeing white exhaust, don't crank more than 10 seconds. You need some more heat in the cylinders. If you want to put the time into it, use a blow dryer or heat lamp to heat the oil bath filter. It’s slow but it will dump serious heat into the process. Heat in a diesel is like a spark to a gas engine.

If you crank and there’s no combustion and no unburned fuel, you have a delivery problem. Check your fuel tank, bleed your fuel system at the filter and at the injection pump. Make sure the kill handle is pushed in and the kill actuator at the injection pump has released back to the “run” position.

If loosening the bleeding screw at the injection pump allows the free flow of fuel, it’s either the wrong fuel, bad fuel injection pump (insufficient pressure), timing injection cam is completely out of whack or injectors are completely clogged. If you’re at this point it means you probably want to see a pro. If you still don't get vaporized fuel, you can back out the injectors and confirm that no fuel is atomized, but without a fuel pressure tester and other gadgets, you won't be able to diagnose the problem.

Theoretically, you aren't supposed to need glow plugs unless it's cold but I use them all the time on the first start of the day. If it won't start, heat up the oil bath air cleaner with a heat lamp or a blow dryer.

If it isn't starting even when cranking at 400 RPM, you can try the compression release to try and coax a higher cranking speed, but I've seen only limited success with the compression release.

If you are cranking fast enough and getting fuel, and have applied heat and it still won't start, you can try a very small amount of starting ether in the intake. This is not recommended by most diesel manufacturers for several reasons. Use ether at your own risk. I take no responsibility for damage you do to your engine. But it pretty reliable if you have an urgent requirement to get the motor started. Use very little.

Some Technical Data

Here’s a page full of handy technical specifications